The invention relates to a beverage feeding apparatus of the so-called xe2x80x9cpost-mix systemxe2x80x9d wherein a concentrated beverage is diluted with diluting water according to beverage feed operation. More particularly, the invention relates to a beverage feeding apparatus which can provide a beverage at a predetermined dilution ratio even when the amount of the diluting water fed has been varied by some cause.
Among beverage feeding apparatuses for feeding various beverages through nozzles, one of representative beverage feeding apparatuses is the so-called xe2x80x9cpost-mixxe2x80x9d system wherein a stock beverage and diluting water are fed through respective separate feed passages and are mixed together in the nozzle or a cup according to beverage feed operation. This system is disclosed, for example, in Japanese Patent Laid-Open Nos. 46983/1999 and 29698/1998.
When this beverage feeding apparatus of post-mix system is based on a selling system utilizing push button switches provided for respective types of beverages, this system is the so-called xe2x80x9csemi-automatic selling systemxe2x80x9d wherein as soon as a person who desires the feed of a certain type of a beverage has depressed a push button switch corresponding to the desired type of beverage in such a state that a cup is placed on a table located under a feed nozzle, a control unit is operated to feed a predetermined amount of the beverage through the operation of a timer for a given period of time. This automatic selling system is the so-called xe2x80x9ccup-type vending machinexe2x80x9d wherein the insertion of money and the operation of a push button switch permit a cup to drop on a selling port and, in addition, a given amount of a desired beverage to be fed into the cup.
When the beverage feeding apparatus is based on a feed lever system wherein feed levers are provided for respective types of beverages, a switch is in an ON state during a period wherein a person who desires the feed of a certain type of a beverage is operating the feed lever corresponding to the desired type, thereby permitting a solenoid valve to be opened (the so-called xe2x80x9cmanual feed systemxe2x80x9d).
Recently, for example, in family restaurants and fastfood restaurants, there is an ever-increasing tendency for adopting a selling system known as the so-called xe2x80x9cfree drinkxe2x80x9d as a self-service system wherein the above-described beverage feeding apparatus is installed on a place at which guests can operate the apparatus. In this case, a guest can operate a lever or a push button switch provided on the front face of the beverage feeding apparatus to freely pour a favorite beverage into a cup.
Japanese Patent Laid-Open No. 301496/1997 discloses an apparatus based on a system such that, when syrup fed from BIB (bag in box) as a container storing a certain type of syrup as a concentrated stock beverage is diluted with diluting water, the amount of syrup fed from BIB is preset through a numeric value input key, such as a ten key, and the syrup is diluted according to the dilution ratio based on the set value.
According to the method described in Japanese Patent Laid-Open No. 301496/1997, the dilution ratio is specified by the set value. When the flow rate of the diluting water falls within the specified range, a beverage having predetermined quality can be provided. On the other hand, when the amount of the diluting water has been lowered by some cause, such as leakage of the diluting water, the operation of a lever or a push button switch by a customer (or a guest) without noticing this trouble poses a problem that a beverage containing a smaller amount of diluting water than the predetermined amount, that is, a beverage having a high concentration and poor quality, is fed into the cup.
In view of the above problem of the prior art, the invention has been made, and it is an object of the invention to provide a beverage feeding apparatus which can provide a beverage at a predetermined dilution ratio even when the amount of the diluting water has been varied by some cause.
According to the first feature of the invention, a beverage feeding apparatus for mixing a stock beverage fed from a storing container with diluting water according to beverage feed operation comprises:
a stepping motor for driving a stock beverage feed pump for feeding the stock beverage;
a flow meter for generating a signal of which the period varies depending upon the amount of the diluting water passed through the flow meter; and
means for varying the amount of the stock beverage fed by the stock beverage feed pump by varying the period of the drive signal of the stepping motor based on the amount of the diluting water passed through the flow meter.
According to the second feature of the invention, a beverage feeding apparatus for mixing a stock beverage fed from a storing container with diluting water according to beverage feed operation comprises:
dilution ratio setting means for setting a predetermined dilution ratio;
reference clock signal generating means for generating a reference clock signal of a predetermined frequency;
a flow meter for generating a continuous signal of which the frequency varies according to the amount of the diluting water passed through the flow meter;
frequency divider means for dividing the reference clock signal at a frequency dividing ratio based on the dilution ratio and the continuous signal to generate a frequency division signal;
driving means for generating a drive signal of a period based on the frequency of the frequency division signal; and
a driving motor for driving a stock beverage feed pump for feeding the stock beverage based on the drive signal,
the period of the drive signal being varied based on the amount of the diluting water passed through the flow meter, thereby varying the amount of the stock beverage fed through the stock beverage feed pump.
According to the third feature of the invention, a beverage feeding apparatus for mixing a stock beverage fed from a storing container with diluting water according to beverage feed operation comprises:
dilution ratio setting means for setting a predetermined dilution ratio;
reference clock signal generating means for generating a reference clock signal of a predetermined frequency;
a flow meter for generating a continuous signal of which the frequency varies according to the amount of the diluting water passed through the flow meter;
frequency divider means for dividing the reference clock signal according to a frequency dividing ratio based on the continuous signal to generate a frequency division signal;
driving means for generating a drive signal of a period based on the frequency of the frequency division signal; and
a drive motor for driving a stock beverage feed pump for feeding the stock beverage based on the drive signal,
the frequency of the frequency division signal being varied based on the continuous signal.